Greetings all,
I have one 220 outlet in my shop and two pieces of equipment that use it – the bandsaw and the drum sander. I am getting tired of plugging and unplugging each unit in order to use them. Is there some sort of, say, a “Y” pig tail for 220v I can use? Is a Distribution or “spider” box useful in this case? I don’t intend on powering both units at the same time, so I don’t think amperage is an issue here. Thanks for your valuable input.
ATOMA
Replies
just get yourself a junction box with a couple of receptacles and a piece of 10/3 or 10/4 extension cord and screw it to a piece of plywood scrap. Depending on how much extension cord you need, you are probably looking at about $15.
Here's my little extension setup, it's a single outlet but you could easily make it a double. I can't remember why I did it this way instead of making a simple extension cord, but I think it was because I happened to have the receptacle and other parts lying around so I used them.
That's a pretty good setup.
by the way, if you get 10/4 bulk extension cord you could use the neutral to wire up a 110v receptacle in addition to what you need for the 220v.
I believe that wiring a 110v with 220v may contravene the code when wired that way
got a reference for that?
"I think wiring a 110v with 220v may contravene the code when wired that way."
I don't think that is true. That is why we have four conductor cable. If my memory serves me right, the code is changing or has recently changed to require four conductor cable wiring for appliances that use both 110v and 220v. Perhaps a seasoned electrician will chip in.
Tinkerer3,
I think jako17 misunderstood and thought you were talking about connecting 240 volts to a 120 v outlet which would be against code.
Jack
Oops, not what I meant at all. In a 220 v circuit, if the neutral is brought along as a fourth wire one can with the proper receptacle and plug, plug in an appliance that requires both 220 v and 120 volt. Is that better?
Yes, in fact it is quite common to have both in appliances like electric dryers (240 v heaters and 120 v motors and timers) and ranges (240 v elements and 120 v lights).
Jack
Many, but not all, 220 circuits have no neutral wire. Your suggestion of splitting off a 110 would not work for them. But if the neutral were there it perhaps might still not be a great idea depending on designated loads and the intended use of this new 110 circuit. For anyone unfamiliar with electricity and electric service, I'd suggest they consult a qualified electrician before delving that deep into what could be a shocking experience. (the pun was intended, sorry)
220v doesn't require a neutral, 2 hots and a ground. However, you can split off one hot and wire it with the neutral and ground to have a 110v circuit, which is exactly what happens when you have a 220v machine with an integrated light. It's also how electrical dryers work. This is also why there is 4 wire extension cord.
My point is there may very likely not be a neutral wire in the outlet box.To the OP. Simply get a duplex outlet rated for 220. Have an electrician install it in place of the single you now have. Or, only if you are comfortable, do it yourself. Not everyone is eager to, nor should, become their own electrician, no matter how "easy" it seems to you.
Can you run some 10 gauge in conduit from the existing receptacle to a spot close to the second machine? You'd need two hot wires and a neutral.
Then, no need to plug and unplug.
kreuzie
220V is restricted as to 15 A or 20 A service correct? The tools you are running are likely both 15A.
You don't say if your outlet is a single or duplex style outlet. You should be able to install a duplex receptacle of the correct amperage rating so both tools can plug into one circuit.
Don
Honestly, I don't know if the outlet is a single or duplex style outlet - it has three wires, not four (does this help?). What I understand you saying is that I can install another wall outlet feeding off the same wires as the first? Thanks.
If the outlet has provision to accept two plugs at the same time, it is duplex. If it will only fit one then it is a single.
For peace of mind them I strongly recommend that you consult with your local electrical inspection office or an electrician and make sure.
Electrical advice is cheap but whatever your local inspector will accept is what counts in the end.I am going to assume that if you cannot plug in both machines at the same time you have a single receptacle not duplex. You do not find many 220V "convenience devices" on the market in North America because 220 is primarily used for larger stationary home appliances.Get a qualified person to make the changes required. It may cost a few bucks, but if you try it on your own and mess up, your ability to continue using your shop could be severely impaired.Don
"Get a qualified person to make the changes required. It may cost a few bucks, but if you try it on your own and mess up, your ability to continue using your shop could be severely impaired."Or you could end up learning how to do it... electricity is not hard, it's very logical and behaves in a predictable manner. There are ample resources online and in print, and with the appropriate attention to safety, diligence, not cutting corners, and patience, well anyone can learn to do electrical work at this level. I change my own oil too.
That would be ATOMA'a decision, not yours or mine.I have no doubt that I could resolve his issue in a very short period of time but I am here and he is there.Better to err on the side of caution and live to enjoy life.Don
You change your own oil... Wow there is a man who is really living on the edge. Just kidding. I agree with what you are saying. Why should we be so afraid to tackle these things. With a little common sense the vast majority of things in life can be tackled. For everythng else there is stupidity.
Derek
Don,
I whole heartedly agree with you. If you ask these guys who "change their own oil" what the National Electric Code is most won't know. Those that do know probably couldn't tell you under what article to find requirements for definite purpose outlets, motor feeder sizing or sub fed panels.
I'm an electrical engineer who started out as an electrician many years ago. I seldom reply to electrical questions here because I've been flamed by the "do it yourselfers" too many times. These are usually the guys who "hook three receptacles in series", or show their lack of knowledge in some other way.
My and my family's health and safety are too important for me to put them at risk trying to cut corners by doing something I'm not qualified to do. In the immortal words of Dirty Harry, "A man's got to know his limitations." I don't understand people who spend $700 on a tool but won't spend $150 to have it properly installed by a qualified professional.
My best advise for these jake leg electricians is: Keep your fire and health insurance policies nearby. You could have a need for them soon.
OK, let the flaming begin...
Not a flame, just a question. As someone who has three outlets in a series properly sized wire/outlets/breaker to meet equipement requirements, what is the risk? again a serious question. Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
Outlets are not put in series, they are put in parallel.
He said three outlets in a series not three outlets in series. It is permissible to have a series of outlets wired in paralell.
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Men will never be free until the last king is strangled with the entrails of the last priest.~ Denis Diderot
Thanks for the correction. that's what I meant wrong words.Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
Outlets are not put in series, they are put in parallel.
Umm, are we talking standard residential wiring here? Because, if so, that is not necessarily true -- receptacles are wired in series or parallel, or both, depending on what is needed from the circuit. Each has it's advantages and disadvantages:
With series wiring if there is a defective receptacle, all the devices after that one in the circuit will not work. Think Christmas tree lights. This can make troubleshooting an electrical problem a little easier. A circuit of 6 receptacles with the first two working and the last four not tells you that there is a problem with the third receptacle in the series. The downside is that, in our example, none of the receptacles after the third one are working, and could leave an important device or component without power.
With parallel wiring if there is a defective receptacle, all the devices in the circuit will work except the defective one. The advantage is the remainder of the circuit remains functional. The disadvantage is that it might not be the receptacle that is defective but the device plugged into it. Your clock isn't working so you change the receptacle thinking it's a dud. Plug the clock back in and it still doesn't work because the clock is dead. You wasted your time and a buck swapping out a receptacle. That may seem preposterous, but believe me, it's been done (not by me).
As well, you can have a parallel circuit with one or more series circuits branching off it. This is done a lot with new old construction where additional receptacle or lighting circuits are added to an existing electrical system.
Most states or localities allow homeowners to do their own electrical work. The problem that arises is that many do but never have it inspected. Their really is no problem with doing your own work -- or changing your own oil -- provided you do what should be done -- have it inspected. You can save some money, learn something, and have a wiring job that you know is safe and code compliant because you had it inspected!
BTW, I am an electrician, well, I was before I did a career change a number of years ago.
Edited 10/24/2008 12:03 am ET by pzaxtl
Edited 10/24/2008 12:04 am ET by pzaxtl
A series of electrical outlets (outlets being defined as a receptacle the appliances or tools plug into) would not be wired in series for a couple of reasons. If nothing was plugged into the first outlet in line the outlets downstream would be dead. The other reason is that all outlets would be limited to the current drawn by the smallest device plugged in. If you had a 20 watt lamp in the first outlet the 1500 watt heater in the second would only run at 20 watts.
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Men will never be free until the last king is strangled with the entrails of the last priest.~ Denis Diderot
Pxaxtl, I think I see the problem in the series/parallel argument. In engineering terms, "series wiring" refers to wiring like this:
POWER ---------[load] ----------- [load] ------- [load] -----| |NEUTRAL -----------------------------------------------------|
That's how the little (not C-7, e.g.) X-Mass lights are wired.
I have never seen outlets wired in this manner nor can I imagine an instance where they would be.If they were, any load use would reduce the voltage in all the other outlets in the series. (In the Christmas light example, the series-wired bulbs are each running on only a few volts, depending on how many lights are in the string.) To wire outlets this way, you'd have to connect both the incoming and outgoing black wires to the device and just run the neutral straight through. In fact, wired this way, if there was a problem at any outlet, NONE of them would worr, not just the downstream ones, since the circuit would be broken. That's why on the cheaper X-Mass lights, if one goes out, they all do.
Rather, outlets are wired in parallel:
POWER -------|--------------|-----------| [load] [load] [load]NEUTRAL------|--------------|-----------|
The problem arises because many describe this wiring scheme as wiring outles "in a series".
While they may be wired "in a series", they are not wired "in series". It's just semanitcs, not a true disagreement.
Mike HennessyPittsburgh, PA
Edit: DUH! I just saw dgreen's post. He's right, of course. In a true series wiring scheme, no outlet would work unless something was plugged in to all of them.
Edited 10/24/2008 7:06 am ET by MikeHennessy
Well, I could add some details on resistance and impedance but it looks like you guys have it explained pretty well. Have a good evening.
pzaxtl,<!----><!----><!---->
If you wire receptacles in series how do you overcome the voltage drop after each receptacle?<!----><!---->
Voltage is the same in every branch of a parallel circuit. Current is the same in a series circuit.<!----><!---->
You cannot wire receptacles in series and run more than one load at a time at rated voltage. And, wiring receptacles in series is a violation of the National Electric Code.
I agree that all DYI work should be inspected. But if the inspector finds receptacles wired in series you better have some smelling salts handy...
"You cannot wire receptacles in series and run more than one load at a time at rated voltage. And, wiring receptacles in series is a violation of the National Electric Code."It is code and it is done ALL THE TIME.Power is connected to one set of terminals on the receptacle. Wires to the next receptacle connect to the other set of terminals.Remove that receptacle and all of the those down stream are dead.The RECEPTACLES are wired in SERIES.It is a confusing phrase.But they are in series.But it is not a series circuit..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Receptacles are NOT wired in series, (I'm speaking of electrical series here. And I think you'll agree about that.). While I understand that a series of receptacles can be "daisy chained" by wiring them as you say, it is not good practice. Why would you allow all of the receptacles "down stream" from the one you removed to go dead? Best practice is to use pig tails and wire nuts so that if a receptacle is removed others down the line are still energized. Unfortunately, in this day of the "lowest bidder" speed of installation trumps quality of installation. So, many contractors wire in the "daisy chain" fashion.
If you TRULY wire receptacles in series and you plugged more than one load into the "string" of receptacles none of them would run at full voltage.
To clarify: 120 V ----| |----| |----| |---- N = series
120 V N
|------| |----|
|------| |----|
|------| |----|
= parallel ^
Edited 10/30/2008 12:16 pm ET by northhouguy
"While I understand that a series of receptacles can be "daisy chained" by wiring them as you say, it is not good practice. Why would you allow all of the receptacles "down stream" from the one you removed to go dead? Best practice is to use pig tails and wire nuts so that if a receptacle is removed others down the line are still energized."
I've always struggled with this choice. I can see the benefits of both ways.
Pigtails are good, 'cause you can remove the receptacle without breaking the circuit downstream. However, since I rarely have to remove one without shutting down the power to the circuit, I don't see that as much of a benefit.
On the other hand, with good receptacles, the connections under the screws are, IMHO, a bit better than wire nuts, so that's a point for not using pigtails in a single-receptacle box. Less wire in the box is another point. Another point awarded because, if there's a problem with a receptacle, you may actually want the downstream circuit to go dead to make the problem more immediately apparent.
I always use pigtails in a box with more than one device. But on boxes where there is only one receptacle, and it's wired through, I find myself "daisy chaining" more often lately. Especially with decent back-wired receptacles.
Mike HennessyPittsburgh, PA
Switches are always wired in "series" and receptacles are wired in "parallel." If switches were in parallel, they would not open and close the circuit. If receptacles were wired in series, you re quite right in saying each successive appliance you plug in would receive less amperage until eventually nothing in that circuit would work properly.
Actually if the outlets are wired in series the loads would all receive the same amperage but varying voltage. In a series circuit the resistance is the total resistance of all the loads and each load would drop voltage. If you connected three 1500 watt loads in series the total load would be 4500 watts. If you apply 120 volts to 4500 watt load the circuit would draw 37.5 amps which would flow through all the loads. the first 1500 watt load would drop 40 volts the second 40 more and finally the last load would drop the last 40 volts.
Jack
"If you connected three 1500 watt loads in series, the total load would be 4500 watts."
I think you are confusing series with parallel. It has been a while since I've worked with these figures but using the formula I = P X E = 1500/120 = 12.50, it follows that one 1500 load = 12.50 amperes. Using the formula E = I X R, we get 120/125 = 9.60 Ohms. Since there are 3 loads of 9.6 ohms the total resistance is 3 x 9.6 = 28.8 ohms total. Using the I = E/R formula again we get 120/28.8 = 4.16 amps. And finally the P = I X E formula we get 4.16 X 120 = 499.2 watts instead of the 4500 watts you quoted.
The load drop for a series is right - 120 volts divided by 3 equals 40 volts per load but the problem with this is that in a resistance circuit of only 40 volts per load, the heat buildup would be much less than for 120 volts. The resistance is dramatically lower for a conductor of lower temperature so the real way to find the resistance and power usage is to test them in place.
OK, now could ye possibly relate all that brainfood to me?
I have a 30 amp 220v breaker in me main panel that has a run of 10-3 for a length of < 30'. At the end of the run are 2 - 20 amp receptacles. I have connected everything Red to Red, Black to Black & White to White - Ground to Ground coming from the main panel.
Plugged into the first receptacle is a dust collector that draws 7.5 amps, not sure what it draws on starup. Plugged into the second receptacle is a Table Saw that draws 11 amps, again not sure what it draws on startup.
Now I aint holdin a gun to your heed but if I start up both machines will I burn down the house? Assuming it aint rainin of course.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
You won't burn the house down if you start them at the same time but you may trip the breaker.
Jack
Jack,
I haven't actually done the scenario that I posted but it has crossed my mind. In practice I would never power up both machines at the same time anyway as I feel the DC should be fully up to speed before expecting it to do its job. But more importantly I do realize that either machine drwas more amps on startup than when it is up to speed.
One could also trip the breaker should one or the other bog down or could one burn out a motor in this situation?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
A 30amp service for a motor that draws 7.5 amps is heavy enough you could burn up a stalled motor before it trips the breaker. You could install inline 15amp fuse on that circuit and a 20 amp inline fuse on the other.
Jack
Thanks Jack,
So in the interests of clarity for me, in laymans terms, one should match the circuit capacity with the tool that is to be connected to it. Or in an ideal situation, each tool should be on its own circuit.
I apologize for being so stupid about this but want to make sure I do the right thing.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
By code you should have 30 amp outlets on a 30 amp circuit. The breaker protects the wiring and outlets. Having said that, the 20 amp receptacles, though not up to code, will probably be OK because electrical devices routinely have a 50%+ safety margin. That is, a 20 amp receptacle is designed and tested to take at least 150% or 30 amp current.Chances are you have a breaker built into your saw, that should protect the saw, the dust collector may also have built in protection either amperage or a thermal overload. You can change the recepticles and plugs to 30 amp rated ones and be up to code.
Jack
The bomb is set and it is raining cats and dogs. All you need to do is turn the switch on. Ha Ha.
Actually 7.5 amps plus 11 amps equals 18.5 amps on a 30 amp circuit. Sounds good to go to me - well within the 80% safety margin. Breakers generally have startup protection so should take care of overload for a second or two. One thing that bothers me is your 20 amp receptacles. I assume they are hooked up as 220 volts to each receptacle and not two 110 volt receptacles. If you have a 30 amp breaker, then nothing in that circuit should be rated less than 30 amps. Your individual motors should have their own protection, either internally or externally. Your being right their to pull the cord if something goes wrong should give them some protection.
Tinkerer,
I assume they are hooked up as 220 volts to each receptacle and not two 110 volt receptacles. If you have a 30 amp breaker, then nothing in that circuit should be rated less than 30 amps.
OK, in the interests of education/learning, suppose I were to put in a sub-panel and run the 30 amp ciscuit into it. From there I insert a 20 amp breaker for the TS and a 15 amp breaker for the DC. In this scenario I see the sub-panel acting as a splitter.
Also I would then be 5 amps over the capacity of the circuit but as long as I don't power up each machine at the same time I should be well within the capacity of the 30 amp circuit.
What I'm trying to do here is understand what is good practice with regard to electrical wiring for my own application and contribute to the OPs original question. All in all it seems to me that using a sub-panel is the right way to go when trying to split a 220v line. After all that is the purpose of a panel in the first place, right?
All this begs the question "I wonder how many electrical panels out here are rated for 100 amps and if you add up all the amp ratings of the breakers in the panel, the total exceeds 100 amps?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Taunton Press published a book by Rex Cauldwell on electric wiring. He has the clearest descriptions and instructions for electric wiring that I have seen. The wiring that you are contemplating is too important. Get Cauldwell and go with the best.
BJ Gardening, cooking and woodworking in South'n Murlyn'
"All this begs the question "I wonder how many electrical panels out here are rated for 100 amps and if you add up all the amp ratings of the breakers in the panel, the total exceeds 100 amps?"
It doesn't matter how much the individual breakers add up to. The individual breakers protect the wiring connected to them, the main breaker prevents overloading the service so in theory you could have 1000 50 amp breakers (exaggeration but true) in a 100 amp box. the 1000 breakers would prevent any one circuit from exceeding 50 amps and the main would prevent the total draw doesn't exceed 100 amps.
This exaggeration is only to demonstrate the purpose of the breakers not a suggestion to try it.
Jack
Edited 11/4/2008 10:57 pm ET by JLMCDANIEL
Tinkerer3,
Your calculations are correct. I said watts then used the formula for resistance. However my point was that what ever current is flowing through the first load in a series circuit is the same as the current flow through all the loads of a series circuit. and that the voltages would be different proportional to the resistance of the individual loads.
Jack
Yeah, that sounds better. Generalizations rather than actual figures. I think we agree that loads in series are a no no?
In my shop, I have a wall switch wired in parallel with a timer switch to operate the air handler. If either or both of the switches are on the air cleaner is running. The AC is off only when both switches are off. If I am working in the shop and want the AC running until I leave I flip the wall switch on. If I leave and want the AC to run a while longer I set the timer. Actually, I haven't mounted the air cleaner yet. Soon,
Edited 11/4/2008 9:24 pm ET by Tinkerer3
Having those two switches wired in tandem like that makes some sense. As you point out, having them wired in parallel requires both of them to be turned off in order to break the circuit and shut everything down.
I forgot to mention that I also have secondary/security lights (that consist of three 100 watt bulbs) wired that way also. When I enter the shop and don't need bright lights I just turn these lights on to get what I want or find what I need. When I leave, I can turn the motion switch on so when someone enters, the lights will turn on and the camera can take a picture and send it to the computer in the house. The primary lights are some over 1700 watts that give me plenty of light to work with.
The point I want to make is it really doesn't matter what you or I accept as risk. We know our individual abilities and our individual risk tolerance.
The individual who has the concern has to make is own decision based on his skill level and risk tolerance.Don
Yes, that may be, but you would be a fool if you didn't speak up to save a person an injury.
I don't know if you are agreeing with me or not. I thought I was pointing the originator towards getting qualified assistance with his problem.Don
OK, let us put it this way, A blind man is just about to walk over a cliff. I think it is your duty to alert the man of the danger of continuing that path. Maybe I posted to the wrong person.
Edited 10/27/2008 11:50 pm ET by Tinkerer3
I think so. I felt I was doing the right thing referring ATOMA to seek qualified assistance.
No worries. This thread has gotten so far away from helping the guy....
Don
Edited 10/27/2008 9:03 pm by Don01
I have two machines in my woodshop that I want to wire as 220v machines; a new 2 HP Unisaw that requires 11 amps and a 1½HP dust collector (currently on 110 but I want to convert to 220) that requires 7.5 amps.
Sooooooo, after reading all the posts in this discussion I come away with the following:
Run #10 wire (what kind - 2 wire, 3 wire?) to a 60 amp subpanel off a 60 amp breaker in the Main panel. This run is ~ 30'.
Then install a 20 amp breaker for the Unisaw, and a 15 amp breaker for the dust collector and run #12 to each machine - less than 8'. This will leave me with 25 amps left in the sub panel, right?
As ignorant as an oyster when it comes to electrickery,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob, note that if the DC runs on 7.5 A on 120v, it'll use only about 1/2 that on 240 v.
Mike HennessyPittsburgh, PA
MIke,
Me brain not engaged B4 typing.
I meant to say the DC uses 7.5 amps on 220v, 15 amps on 120v.
Also, for the 30' run from the main panel to the 60 amp sub panel I think I will need #6 wire, but am not sure about that. From the breakers in the sub panel I should be OK with 12-2 to each machine.
Please tell me if I'm full of horse balls.
Regards,
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Firstly... if you want a sub-panel and you don't know patootie about electricity, then hire an electrician.Secondly... I'm not an electrician, only a guy who's done a fair amount of his own work. But, I think that you don't really want a sub-panel. Simply wire from the main panel to the two new receptacles.... two new circuits. I believe that sub-panels have a whole set of rules specific to themselves and you may not be meeting those requirements. Grounding is one thing that you may be overlooking. The code has to consider that someone other than you, in the future, might use this panel for something else, so it must be designed for that eventuality.
The 60 amp sub panel will pull its ground from the MAIN panel.Not an electrician either but did manage to wire 300 amps (200 main & 100 amp sub) in a new house + connect the separated garage/barn direct to the class 320 while hot.It may have been different story if the homeowner didnt tell me the kitchen lites where still on when I though I had the class 320 on bypass,
but moved the lever just a little too far.Now that could have been a little interesting.My suggestion to anyone WIRING 220 circuits that will be covered.
Run 10 gage wire, you never know when you might upgrade to a 3HP
machine that draws just under 30 amps.When I upgraded to 3HP Planer and Table saws, I toyed with the idea of how to run 10 gage wire without ripping apart 40 foot of wall.
When I pull the 1 recepticle and FOUND 10 gage wire,
I realized the guy that wired it was pretty sharp; unfortunately,
his memory isnt so hot anymore.
Oh yeah, my shop was my first wiring project some 11 years ago.
OK, I've done a fair amount of wiring before in this house, including a 110v sub panel in the horse barn w/underground wiring and a sub panel, but all of it has been 110v. The only 220v wiring I've done is our new stove here, about a year ago. No problems so far.
Let's just say I have a healthy respect for electricity and am not going to do the actual wiring myself. What I would like to know is what is the right way to do it so I can get the necessary parts.
I'll basically be doing all the grunt work getting everything in place for an electrician to actually hook everything up and test it. Also, I'd like to learn more about it, not just plug in the tools.
I do appreciate your concern.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I think if you are wiring for more than fifty amps, you should put in #4. Expensive but don't economize by using undersize wire. One poster suggested not using a sub panel. That depends on a lot of factors - room for more breakers in the main panel, distance between your shop and the main panel among others. If you are limited on breaker spaces in the main panel, I would certainly consider a sub panel. I don't like sub panels scattered all over the building but they have their place. You mentioned number of conductors. You must have four conductors from the main to the subpanel - ground, neutral and two hot. I'm not sure, but I think the last code requires four to the receptacle also. That allows for a machine that requires both 220 and 110 (kitchen stove). Any 220 circuit requires at least three conductors - a ground and two hot wires.
Edited 10/30/2008 10:25 pm ET by Tinkerer3
Edited 10/30/2008 10:28 pm ET by Tinkerer3
Edited 10/30/2008 10:29 pm ET by Tinkerer3
because reading the NEC, local building codes (available online mind you) and understanding the fundamental theories of electricity are sooo hard. There was a time in this country when self-sufficiency meant something, I subscribe to that theory and disabuse myself of the notion that "it's too hard" by looking at the yahoos that are found in every trade. Electricity hasn't changed, the way we safely use it has evolved and all of that knowledge can be acquired and put to good use by anyone who can read, has a minimal IQ, and appreciates the consequences of ignoring safety. Wiring a receptacle in a shop isn't hard, doesn't require alerting the media, or taking an advanced degree in electrical engineering. On a somewhat related note, it's really a shame that trade and vocational programs have declined in recent decades.
Hi, Don - Not quite right. Current rating is simply a function of wire gauge - more current = larger wire. As an example, the service to your house may be 240volt/60cycle/1phase rated at 200 amps - probably 250kcm buried cable. That's big cable, and certainly not usable for drop cords, but it demonstrates the point. Both 40A and 60A are common 240v distribution boxes - I'll bet there's a fused box at your house air conditioning unit (if you use one.) The rule is that the wire must be sized to carry the largest current needed for intended connections, and that the upstream fuse/breaker must be sized to protect the wire from overcurrent (which generates too much heat and damages the insulation.)There's a handy little electrical reference book called Ugly's (4"x6", 186 pages) available at Home Depot (and Lowe's, I'd guess) that has all of the tables (and a lot more) in it. It is NOT a design manual, and the advice elsewhere to obtain the services of a knowledgeable electrician is exactly correct.SO Cord ("hard servce") is commonly available in sizes #18AWG through #2AWG, and with two or more conductors. That's the black rubber-jacketed stuff used for drop cords. For a shop, all three PLUS ground (4 conductor) are available, but 2-conductor with ground is certainly applicable for direct connecton of 240v machines. Type "SOW" adds wet service capability, and "SOOW" adds oil-resistance. Ya runs what ya needs ....Lawful common ampacities:
#14 = 15A
#12 = 20A
#10 = 30A
#2 can carry at least 95A - whew! I have exactly the situation that started this thread. As it turned out, I had a 40A/240v receptacle installed for "future use" when the house was built. I made a simple duplex 240 box with hardware store parts, and SO drop cords for DC, planer, and air compr. Actually, they're all plugged in with plenty of capacity to run all at once. Eventually, I'll install my second 200A service and hard wire the entire shop (this extension cord business makes things possible quickly, but it ain't no way to run no danged railroad...)It's indeed possible to feed something like a 40-60A auxiliary panel right off your home's main panel (if there's room for a breaker,) and locate the aux panel at a place convenient for use in the shop.
The following reference will give you several options for Leviton 125/220v 20a duplex receptacles: http://www.onestopbuy.com/Duplex-(Best)-12212.asp
I have used these in two shops over the past 10 years with great success.
Doug
I just wired in two 220 circuits to my new basement shop. One for the DC, and a second for all the other tools(BS,TS,Jointer). In my old shop I had a single plug and I made an extention cable and just shared. In my new shop, like you, I'd had enough. To solve my problem 3 drops one circuit (keep in mind I could never operate two devices at the same time), I put in three recepticles in a series with pig tails to connect to the L6 20 recepticles (so you can't put a 110 appliance in by accident (|-). and bonded the grounds. I used wire nuts and put in deep wall boxes. It's nead and stop the constant unplugging and plugging in. For my equipment 20A is all that was required so 12/2 & 20A recepticles was required. Consult your power consumption requirements. If its greater than 20A, at a minimum go to 10/2 for your line @ 30A rated plugs. Remember Amp rating needs matching breaker/wire/recepticles. As other have mentioned some areas may require sep circuits if you have to inspect.
If it moves, tax it. If it keeps moving, regulate it.
And if it stops moving, subsidize it.
I moved shops last year, and had my electrician come install a sub panel and some 220V receptacles. Like in the previous shop... This time he installed duplex receptacles instead of singles... so now I have double the amount of plugs... and of course I paid for each receptacle. Oops. He's a good guy though and did it fairly cheaply so it wasn't a big deal.
You can get a Y cord for this, in either 3 or 4 terminal. If your local hardware or big box doesn't carry them, go to a marina that sells/services large boats- they use the same kind of cabling and cords for shore power.
I have never seen so many disagreements on what should be a standard way of looking at things. What scares me that there are so many "you are wrong" and "I am right" about stuff that could be VERY dangerous if done the wrong way.
BTW, I am not an electrician and hold no right or wrong view on the subject. Because of all the conflicting theories and ways of doing things seen here, may I humbly suggest that you invest a few $$ and consult a qualified licensed local electrician.
Cheers,
Peter
edit add on: A while ago I spliced an addition to a 240V line to run another tool. Said tool requiring a small additional amp draw. It has worked well (I am still alive). I recently added a tool that required a 30 amp breaker so decided to pay for a licensed electrician to do the wiring specifically for it. When he arrived I asked him to look at my other work. After investigating the tool and wiring, he told me I was right on the edge of capacity. Not safe or legal. All it took on my part was a half hour of grunt work to correct and he made the final connections. His time for that? Charged me 10 minutes. Money well spent.
Better life through Zoodles and poutine...
Edited 11/2/2008 12:16 am by PeterDurand
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